Method of obtaining gold



panying drawing. The frame UNTED STATES PATENT OFFICE.

MAYBURY A. BERTOLET, LEVIS KIRK, AND ANDREW M. DE HART, OF READING,

. PENNSYLVANIA.

METHOD 0F OBTAINING GOLD, &0., BY .AMALGAMATIO1\T.

Specification of Letters Patent No.

T 0 all whom t may concern Be it known that we, MAYBURY A. BEnTo- LET,LEwIs KIRK, 'and ANDREW M. DE HART, of Beading, in the county of Berksand State of Pennsylvania, have invented a. n-ew and useful Method ofSeparating Gold and other Precious Metals from Pulverized Earth or Rockby Amalgamation with Mercury, of which the following is a full, clear,and exact description, reference being had to the accompanying drawing,which makes part of this specification, and in which- Figure l,represents a view in perspective of an apparatus suitable for carryinginto effect our improved method of amalgamation, and Fig. 2, representsa vertical transverse section of the same.

Our invention consists, in heating pulverized auriferous earth or rock,preparatory to bringing it in contact with mercury for the purpose ofcausing the precious metal to be more effectually absorbed by themercury and thus separated from the earth, whether the mercury for thusseparating the preciousV metal from the mixture be heated or not.

Our invention further consists in causing the pulverized ore todescendin a shower through a current of heated gas or vapor while being fedinto the channel which conducts it to the mercury, so that everyparticle of the powder will be heated in its descent which is of greatimportance, as the earth will then part with the spangles or particlesof precious metal adherent thereto, much more readily when thus heatedthan when cold. And lastly our invention consists, in an arrangement ofheating chainbers and pipes for receiving and conducting the fluids usedin heating the apparatus mercury and ore whereby a single current ofsteam or other heated fluid circulating through a simple and compactsystem of conduits is made to heat the'apparatus, the ore preparatory toamalgamation and the mercury for amalgamation.

One form of apparatus suitable for carrying into eect our improvedmethod of separating precious metals from pulverized earth or rock isrepresented in the accom- (A) of this machine is made of stoutscantling, well fastened by joint bolts. To the base of this frame (A)is secured a large metallic disk (B). The underside of this disk (B) has9,499, dated December as, 1852.

a chamber (C) fitted to it to receive heated air or vapor, and the upperside is concave and has a rim (o.) projecting up from its periphery. Thecentral or lowest portion of the disk has an aperture made throughitwhich is fitted with a plug or cock The disk (B) forms a wide andshallow pan to contain a pond of mercury, which is for the purpose ofseparating the precious metal from the ore by amalgamation. Above theconcave disk (B) and concentric and parallel therewith a second disk (D)is susended by an upright shaft (E) which turns in boxes (E F) securedtothe cross-timbers of the frame. This shaft (E) is prevented fromhaving vertical movement by collars (c c) above and below the boxes (F).The shaft (E) is hollow, and has a flange formed on its lower end bywhich it is secured to the disk (D) in such manner, that the openingthrough the shaft, and a central opening through the disk (D) shallcoincide. The underside of the disk (D) is convex to make it parallel tothe lower disk (B) eX- cept for a small portion of its diameter at thecenter, where it is concave to receive a double convex disk or shieldplate (G) which is concentric with, and therefore opposite to theopening (e) through the shaft (E), and is held by studs (n n) at asufficient distance from the disk (D) to permit a free communicationwith the interior of the shaft The disk (D) with the shaft (E) isrotated by means of a pair of bevel wheels, one secured to the hollowshaft (E) and the other to a driving shaft supported inthe frame, whichdriving shaft is fitted with a pulley by which it receives mot-ion fromthe engine or other prime-mover through the medium of a belt.

The upper end of the shaft (E) is made bell mouthed and receives thelower end of a funnel shaped chamber (H) which fits tightly into it.This chamber is firmly secured to the frame (A), and its upper part hasa diaphragm (I) secured across it, which is perforated with numeroussmall holes to allow the auriferous sand or earth to run through in aseries of small streams into the chamber (H) below. The sand or powdercontaining the gold is kept upon the diaphragm by means of a rim (J)surrounding the chamber In case the pulverized ore should not run freelyand regularly through the diaphragm (I), the latter may have a jarringor rotary motion given to it, or it may have a stirrer arranged toagitate the ore upon it, and to keepits holes open.

The chamber is connected by a pipe (K) with the chamber (C) beneath thedisk (B), and the former chamber has an eduction pipe (L) and the latteran induction pipe (M). Heated air or steam or other fluid is introducedfrom any convenient or suit-able generator through the tube (M) into thechamber (C) to heat the disk (B) and the pond of mercury (N), and as thesteam or other hot fluid is supplied in a constant stream, it passesthrough the chamber (C) into the pipe (K) and into the chamber (H) andout at the eduction pipe (L), after the said chamber (H), and the showerof pulverized ore passing through it, have been heated. The steainmay bedischarged from 'the pipe (L) into the atmosphere or may be reconductedto the generator for the purpose of saving the heat it contains insteadof dissipating it into the atmosphere. l prefer highly heated steam toall other fluids for the purpose of heating the apparatus, and as thechambers (C and H) are constantly kept filled with it, and as a rapidcurrent is kept flowing through them, there is but little danger ofinconvenience'resulting from condensation as I' propose toI keep thechambers at a 'temperature of not less than about 220o of Fahrenheitsscale.

The ore, whether auriferous earth, sand, or rock, should be finelypulverized preparatory to submitting it to the action of this machine.lt is then placed upon the perforated diaphragm (l) through which it issifted into the chamber (H). As the ore passes down in a shower throughthe chamber (H) it encounters a current of steam by which it is heated.It then enters the revolving shaft (E), and descends until it strikesthe shield plate (G) by which it is deflected laterally upon the surfaceof they mercury. The centrifugal force imparted to the powder by therotation of the disk (D), causes it to pass to the periphery thereof,and while the powder is thus forced out, it is rubbed by the undersideof the disk (D) against the surface of the mercury which is insufficient quantity to be in contact with a considerable portion of thedisk As the disk revolves rapidly, the pulverized ore passes over thesurface of the mercury (N) in an exceedingly thin film, so that everyatom of the powder is brought into contact with the mercury whoseaffinity for the precious metal is great, especially when exalted byheat. After the powdered ore has passed the mercury (N), it isdischarged from between the disks (B and D) into the annular space (P)where it gradually works over the flange and drops down. The purpose forwhich the ore is retained in the space (P), is, that such particles ofthe mercury as may be carried out with the earthy matter may have anopportunity to drain out and fall back into the pond (N).

After the pond of mercury has become saturated with the precious met-alto the desired extent, it is drawn off through the aperture fitted withthe plug (b), and after the amalgam has been thus withdrawn, a freshsupply of mercury is placed between the plates or disks (B and D), bypouring it into the annular space The heating of the ore preparatory tobringing it into contact with the mercury expands the gases in itscellsuntil many of them are fractured and enlarged, thus giving to the ore anincreased degree of porosity. The heat also expands the particles ofmetal much more than it expands the rock in which the metal is embedded.This fractures the rock and loosens the metal. This fracturing` of therock and opening of its pores facilitates the access of the mercury tothe particles of metal within it, and hence this preliminary heating isan efhcient agent in the separation of precious metals from their oresby amalgamation, for the reasons stated but there arey others besidethese which it is deemed unnecessary to mention.

This apparatus may be greatly diversified in form and arrangementwithout any departure from the principle of our invention, but as themodifications are almost without end, it would be superfluous todescribe them, especially as any competent engineer will be able to makethe changes that may be necessary to adapt our invention to theparticular circumstances of each case in which it may be used.

One or more of the parts of our invention and especially the heating ofthe ore or mercury, may in some cases be used in connection with thecommon amalgamators, and their efficiency will thereby be greatlyincreased.

Instead of using the pulverized ore dry, it may be mixed with hot water,and passed through the machine in the same manner as the dry powderabove described, but the method of working the ore in a dry state isdeemed preferable, because it brings the particles of ore into immediatecontact with the mercury without the interposition of even a film ofwater.

Instead of heating` the mercury by means of a heated fluid, it may beheated by the direct application of a fire, to the underside of the diskor pan which contains the mercury.

Having thus described our improved method of separating precious metalsfrom the apparatus, the mercury, and the ore, by means of a Current ofheated fluid circul5 lated through chambers and pipes, substantially asdescribed.

In testimony whereof We have hereunto subscribed our names.

MAYBURY A. BERTOLET. LEVS KIRK. A. M. DE HART.

Vitnesses MATTHIAS MENGEL, J. HAGENMAN.

